I believe a milk bottle also works. But then, I once caught a mouse in the toaster.

Lots of things work for mice, but rats are much cleverer. Quite often a trap will catch one rat, but then the rest avoid it.
I'm hoping to get them used to the guttering/pipe seesaw, by leaving it in place, baited, with another piece of guttering underneath to keep it from working, while they get used to it and get ratty smells all over it. Hopefully that way, they won't wise up to it, even when it's dumping them in the barrel.

I finally got enough bait that I stopped worrying about running out before they were 'dealt with' and started putting it out.
I also had the chickens fully accustomed to the rat-proof feeders by this time, and the coop that they had been breaking into to get food fully rat-proofed.

I was very surprised, after just a few days of putting bait out, that it stopped disappearing. I wondered if they were all hibernating.

A few days before that I had ordered a trail camera, and it duly arrived, so last night I set it up and this morning, I looked at the photo's and . . .
they're not hibernating . . .

depending on the type of poisoned bait they might be drinking a lot and not feeling hungry. some are quite slow acting which is good in case your mutt almost becomes bycatch and vit k from the vet saves em.

they will soon be gone if that is the case,

they may have found a different food supply or they may have stashed your bait in their nest = also soon gone.

if you do try a drop trap let us know how it goes, im curious about them and a multi catch machine would be very useful.

A knowledgeable person told me that even if they didn't get a full dose it would still kill them just take a bit longer. I put it in a really hard to get to spot under a coop, so no worries about pets, and from past experience, I deduce that the rats eat the dead ones. I do keep my eyes open for bodies though.

I have no idea what they are eating, but thinking about what might scare them off, I remembered that I put the tub of bait on the ground handy for refilling . . . close the where I put the bait.

I just reviewed the piccies, and sure enough, they are giving the tub a wide berth. I guess that that wide berth extends under the coop to where the bait is.

I have a rat problem this winter, although I have had no problems before here. I've lost a number of quail through them being not quite so rat proof as I thought.

I have bait boxes and and snap traps out, and so far I have caught two rats and a squirrel in the snap traps, and nothing further. Maybe they can smell a (dead) rat?! There are definitely more rats (and less quail)

I did have a humane mouse trap that worked on a see-saw-in-a-tunnel mechanism. That also worked for a little while, and then no longer. I have an ex-rentokil friend who says that rats don't like new things. It mice are inquisitive.

I suspect that it's grandma and grandpa left, and they're wise to it somehow. I'm surprised that it took so little to kill the rest though. Apart from the two on camera, I haven't seen or heard any for ages though, so I guess it has killed them.

I really need to get working on mechanical traps, and a rat proof run, but it's too bleeping cold!
I guess I'll try the snap traps again, at least they won't smell so new now, so maybe they'll get something this time.

If my understanding is right you'll not be able to buy poisoned bait from April. Only 'competent' persons will be able to. TO be competent you have to pass a course. Mostly this is aimed at farmers and pest control operatives. Householders are expected to pay a pest controller to do it for them at whatever the going rate for a call out is. I think householders can take the course and become 'competent' though I haven't looked into this fully.

If my understanding is right you'll not be able to buy poisoned bait from April. Only 'competent' persons will be able to. TO be competent you have to pass a course. Mostly this is aimed at farmers and pest control operatives. Householders are expected to pay a pest controller to do it for them at whatever the going rate for a call out is. I think householders can take the course and become 'competent' though I haven't looked into this fully.

Sounds a bit extreme, it seems a bit daft you could happily shoot a rat with a 30-06* but would need training to use a baited block of something.